The Data Coordinating Center (DCC) for the Multicenter Clinical Trial of Focal Glomerulosclerosis in Children and Young Adults (FSGS Trial) will coordinate the scientific and operational aspects of a randomized trial comparing alternative therapies for achieving and maintaining remission of proteinuria in this patient population. This proposal outlines our assessment of important clinical, methodological and logistical issues for the design and coordination of a randomized trial in FSGS. Based on this assessment, a protocol for a randomized trial is proposed, and procedures for the DCC's responsibilities in the implementation of the trial are presented. In the planning phase (Phase I), the DCC will work with four Regional Clinical Coordinating Centers (RCCCs) to design and develop a protocol for the trial. Each RCC will oversee several local Clinical Centers (CCs). Systems for data acquisition (via a secure web-based data entry) and data management will be established. The DCC will develop procedures to enhance the quality and completeness of the data collected, including a detailed Manual of Operations describing data collection and other procedures for the RCCCs and CCs. The randomization schedule for entering patients will be generated. The DCC will provide centralized training of study personnel on entry of trial patients, completion of trial forms, and use of the data management system. The DCC will arrange and actively participate in meetings and conference calls of the Steering Committee and its subcommittees. A major function of the DCC during the Recruitment and Follow-Up (Phase II) of the trial will be to monitor recruitment, retention, and adherence to the protocol. The database management system developed in Phase I will be used to assure accurate and complete collection of trial data. An inquiry system will be used to resolve data discrepancies. Trial progress will be reported in monthly reports to the RCCCs, and in reports to the Steering Committee and Data and Safety Monitoring Board. Statistical and interim analyses will be performed with final analyses completed and reported in Phase III. The DCC will develop new statistical methodology as needed to properly analyze the data. Since the FSGS Trial is a multi-centered effort, the DCC will provide leadership to coordinate the trial design and study conduct. The DCC will work to foster a spirit of cooperation which is important to the project.